Apparatus for observing fuel in fuel pressure systems of motor vehicles



Nov. 13, 1956 A. N. MCGURK 2,770,208

APPARATUS FOR OBSERVING FUEL IN FUEL PRESSURE SYSTEMS OF MOTOR VEHICLES Filed April 5, 1955 INVENTOR. ALFRED N MCGURK BY @M -W ATTORNEY M United States Patent APPARATUS FOR OBSERVING FUEL IN FUEL PRESSURE SYSTEMS F MOTOR VEHICLES Alfred N. McGurk, Denver, Colo.

Application April 5, 1955, Serial No. 499,390

Claims. (Cl. 116-117) This invention relates to apparatus for use in observing fuel in fuel pressure systems of motor vehicles and the like, particularly of diesel engines, for the purpose of determining the condition of the fuel and operation of certain parts of the engine.

The main object of the invention is to provide means for use in visually examining motor fuel while it is passing through drain tubes from the injectors of the motor on its return to the fuel tank. Such visual examination of the fuel discloses its condition as well as the condition of the injectors through which it has passed.

Another object of the invention is to provide a plurality of conduits, equal in number to the number of injectors in the motor, each provided with means for detachably connecting it to an injector, whereby the fuel condition and the condition of all the injectors may be inspected simultaneously. Such examination serves to locate air leaks in suction lines leading to the pump or from the fuel filter, partially restricted orifices in return drain tubes, plugged injector cups, scored injectors and unbalanced fuel delivery.

Another object of the invention is to produce apparatus for the purpose stated which is simple in construction and which can be easily and quickly installed after disconnecting the existing return fuel lines from their injectors and from the conduit leading to the fuel tank.

Other objects and advantages will be apparent from the drawing and following specification.

In the drawing:

Fig. 1 is an elevational front View of apparatus embodying my invention, showing one of six return fuel conduits connected to an injector coupling, the other similar conduits being broken away.

Fig. 2 is a vertical sectional view, enlarged, of the manifold block and part of one of the conduits of my apparatus.

In the preferred embodiment of my invention shown in the drawing, 10 indicates a manifold block made of transparent material such as the plastic substance known as Plexiglas. The block 10 is rectangular in cross section and relatively long and narrow. Near its bottom it is provided with a passageway 11 closed at one end by a plug 12 and internally threaded at its opposite open end 13. The end 13 is provided with a threaded connector 14 which is adapted to be detachably connected to a conduit which leads to the conventional fuel tank (not shown) of a motor. The manifold passageway 11 is formed by boring the plastic block and polishing the inner surface of the bore to preserve transparency.

Communicating with the passageway 11 are a pluarility of vertically disposed cylindrical bores which have restricted portions 15 smaller in diameter than the upper cylinders 16. The open upper ends of the cylinders 16 are flush with the top 17 of the block 10. The bores 1516 are drilled and reamed to provide polished inner surfaces so that the contents of the bores are clearly visible through the transparent material of the block 10.

A sleeve 18 made of copper or other suitable material is cemented into the upper end of each bore 16, about half of the length of the sleeves projecting above the top 17 of the block. On the projecting end of each sleeve 18 is mounted the open end of a transparent flex ible tube 19, about twenty inches in length. The tubes fit snugly around the external surfaces of the sleeves 18 and are cemented thereto to make a leak proof joint, with the edges of the tubes in contact with the top 17 of the block.

The opposite free end of each transparent tube 19 is provided with a swivel connector which comprises a short connector tube 20 with thickened ends 21, and a swivel nut 22 provided with a threaded portion 23. The transparent tubing is snugly fitted over one thickened end of the metal tube 20. The threaded swivel nut 22- -23 is loosely mounted on the connector tube 20 and retained between its thickened ends 21, the threaded end 23 of the swivel nut being adapted to be quickly detachably connected to the internally threaded nut 24 of an injector connector 25 leading out of the injector 26.

The number of cylindrical bores 15-16 and of transparent tubes 19 equal the number of injectors in the motor, usually six in a diesel engine.

To use the device of my invention for visual examination of motor fuel which has passed through the injectors of the engine and is en route through return lines to the fuel tank, I first-disconnect the conventional fuel drain tube from one of the injector connectors 25 and substitute one of my transparent tubes 19 by connecting the threaded swivel nut 22-23 to the injector connector 25, repeating this operation until each of the tubes 19 has been connected to an injector connector. The disconnected drain tubes, usually made of metal tubing about seven inches in length, remain connected to the engine manifold, which is then disconnected from the fuel return conduit leading to the fuel tank, and the outlet 14 of my transparent manifold block 10 is connected to the return conduit indicated at 27 in Fig. 1. Thus the transparent apparatus of my invention, includ* ing the manifold block 10 with fitting 14 and the plurality of tubes 19 with swivel connectors 20-23, is substituted for the conventional fuel return tubes and engine manifold between the injectors 26 and the conduit 27 of the engine.

Visual examination of the fuel passing through the tubes 19 and manifold block 10 will reveal dirt or other impurities in the fuel. The passage of the fuel is re tarded to some extent by the restricted bores 15 between the larger bores 16 and the manifold passageway 11, whereby the cylinders 16 hold the fuel sufficiently long to reveal the presence of dirt or other impurities. If the injectors are in good condition and have performed their intended functions in the operation of the engine, the fuel passing through the tubes 19 will be foamy and bubbling, whereas clear fuel, free of foam and bubbles, indicates that the injector to which that tube is connected is not functioning properly, and may be stuck or scored or otherwise defective. The flow of fuel in all the lubes 19 should be uniform and if it is not, the fault can be detected and its location determined.

The transparent tubes 19 of my invention are approximately three times the length of the conventional drain tubes of the engine, and are long enough to permit the user of the device to hold the manifold at a convenient place near the engine for the purpose of visually inspecting the fuel passing through the apparatus and observing the condition of the fuel in the tubes 19.

In describing the invention, reference has been made to a particular example embodying the same, but I wish it to be understood that the invention is not limited to the construction shown in the drawing and that various changesmay be made in the construction and general arrangement of parts without departing from the invention.

I claim:

1. Apparatus for attachment to a motor for observing fuel in the fuel pressure systems of motor vehicles and the like while the fuel is passing to the fuel tank of the motor, comprising a portable transparent manifold block, a manifold passageway closed at one end in the block, means in the open end of the passageway for detachably connecting it to the return fuel conduit of the motor, a plurality of bores in the block each open at one end and communicating at its other end with the manifold passageway, a plurality of transparent flexible tubes, means connecting each of said tubes at one end to the open end of one of said bores, the opposite ends of the tubes being free, and a connector mounted on the free end of each of said transparent tubes for detachably connecting it to the return fuel line of the motor.

2. Apparatus for attachment to a motor for observing fuel in the fuel pressure systems of motor vehicles and the like while the fuel is passing to the fuel tank of the motor, comprising a portable transparent manifold block, a manifold passageway closed at one end in the block, means in the open end of the passageway for detachably connecting it to the return fuel conduit of the motor, a plurality of cylindrical bores in the block each open at one end, a restricted bore between each of said cylindrical bores and the manifold passageway, a plurality of flexible transparent tubes, means connecting each of said tubes at one end to the open end of one of said cylindrical bores, the opposite ends of the tubes being free, and a connector mounted on the free end of each of said transparent tubes for detachably connecting it to the return fuel line of the motor.

3. The apparatus defined by claim 1, in which the means connecting each of the transparent tubes to the open end of one of said bores comprises a short tube cemented into the bore, about half the length of the short tube projecting beyond the manifold block, one end of the transparent tube surrounding the projecting portion of the short tube, and cement between said tubes.

4. The apparatus defined by claim 2, in which the means connecting each of the transparent tubes to the open end of one of said cylindrical bores comprises a short tube cemented into the cylindrical bore, about half the length of the short tube projecting beyond the manifold block, one end of the transparent tube surrounding the projecting portion of the short tube, and cement between said tubes.

5. The apparatus defined by claim 1, in which the connector mounted on the free end of each of said transparent tubes for detachably connecting it to the return fuel line of the motor comprises a short hollow tube provided with thickened end portions and a threaded swivel nut loosely retained on the tube between its thickened ends, one

thickened end of the tube being fitted into the free end of a transparent tube, and the threaded portion of the swivel nut being directed toward the opposite thickened end of the short hollow tube.

6. The apparatus defined by claim 2, in which the connector mounted on the free end of each of said transparent tubes for detachably connecting it to the return fuel line of the motor comprises a short hollow tube provided with thickened end portions and a threaded swivel nut loosely retained on the tube between its thickened ends, one thickened end of the tube being fitted into the free end of a transparent tube, and the threaded 4 portion of the swivel nut being directed toward the opposite thickened end of the short hollow tube.

7. Apparatus for attachment to a motor for observing fuel in the fuel pressure systems of motor vehicles and the like while the fuel is passing from injectors to the fuel tank of the motor, Comprising a manifold block made of transparent plastic material, the block being drilled and internally polished to provide a manifold passageway extending longitudinally of the block, a plug closing one end of the passageway, the opposite end of the passageway being internally threaded, means in the threaded end of the passageway for detachably connecting it to the return fuel conduit of the motor, a plurality of cylindrical bores extending at right angles to the manifold passageway, the bores having open ends flush with one surface of the manifold block, a restricted bore smaller in diameter than the cylindrical bores between and communicating with each of said cylindrical bores and the manifold passageway, the surfaces of said cylindrical bores and restricted bores being polished, a plurality of flexible transparent tubes, means connecting each of said tubes at one end to the open end of one of said cylindrical bores, and a connector mounted on the free end of each of said tr'ans parent tubes for detachably connecting it to an ejector of the motor.

8. The apparatus defined by claim 7, in which the means connecting each of' the transparent tubes to the open end of oneof said cylindrical bores comprises a short tube cemented into the cylindrical bore, about half the length of the short tube projecting beyond the manifold block, one end of the transparent tube surrounding the projecting portion of the short tube, and cement between said tubes.

9. The apparatus defined by claim 7, in which the connector mounted on the 'free end of each of said transparent tubes for detachably connecting it to the return fuel line of the motor comprises a short hollow tube provided with thickened end portions and a threaded swivel nut loosely retained on the tube between its thickened ends, one thickened end of the tube being fitted into the free end of a transparent tube, and the threaded portion of the swivel nut being directed toward the opposite thickened end of the short hollow tube.

10. In combination with a motor vehicle fuel pressure" system including a plurality of injectors, fuel return drain tubes and a return fuel conduit, apparatus'for observing the fuel while it is passing through the return side of the system, comprising a portable transparent manifold block, a manifold passageway closed at one end in the block, means in the open end of the passageway for detachably connecting it to the return fuel conduit, a plurality of bores in the block each open at one end and communicating at its other end with the manifold passageway, 21 plurality of elongated flexible tubes, means connecting each of said tubes at one end to the open end ofone of said bores, the opposite ends of the tubes being free, and a connector mounted on the free end of each of said tubes detachably connecting it to an injector in the return fuel line.

References Cited in the file of this patent UNITED STATES PATENTS 855,167 Essex May 28, 1907 2,345,819 Kirk et al Apr. 4, 1944 2,720,782 Stein Oct. 18, 1955 

